Cooperating microbes convert methane to alternative fuel source

Oil and gas wells and even cattle release methane gas into the atmosphere, and researchers are working on ways to not only capture this gas but also convert it into something useful and less-polluting. Now scientists at the Department of Energy's Pacific Northwest National Laboratory have developed a new system to convert methane into a deep green, energy-rich, gelatin-like substance that can be used as the basis for biofuels and other bioproducts, specialty chemicals — and even feed for cows that create the gas in the first place."We take a waste product that is normally an expense and upgrade it to microbial biomass which can be used to make fuel, fertilizer, animal feed, chemicals and other products," said Hans Bernstein, corresponding author of a recent paper in Bioresource Technology. The PNNL process produces a much cleaner product, either liquid or solid, with simply the flick of a light switch or exposure to sunlight. When there's methane to convert, the cyanobacteria absorb light and use carbon dioxide as fuel to produce oxygen, fueling the methane-munching bacteria. When there is not much methane, researchers dim the lights, reducing the oxygen, which slows the action of the methanotrophs. In recent tests the PNNL team ran the system continuously for about two months.